Illness history: Not associated with remission during treatment of major depression in 515 mood disorder patients

•Subjects (n=515) were treated for an index episode of moderate to severe major depression.•Previous morbidity was compared for subjects reaching clinical remission or not within six months.•Severity and bipolarity (not years-ill, episode counts or rates) were associated with remission.•These findings were sustained among unipolar and bipolar subjects considered separately.

BackgroundThere is suggestive evidence that prior illness history may have little association with response to long-term treatment in bipolar disorder (BD) or recurrent major depressive disorder (MDD), but relationships of illness-history to treatment-response in acute episodes of depression require further testing.MethodsWe tested for associations of selected measures of illness history with remission during treatment of an acute index episode of major depression in 515 mood-disorder patients (327 MDD, 188 BD), using bivariate and multivariate methods.ResultsRemission of depression was more likely with lesser initial symptom-severity and bipolar diagnosis, but not related to years since illness-onset, previous depressions or episodes (based on counts, yearly rates, or %-of months ill), or other indices of illness-severity (hospitalization, co-morbidity, suicide attempt).ConclusionsLikelihood of response to standard treatments for acute major depressive episodes in MDD or BD appeared to be largely independent of prior illness-history.